Extraordinary discoveries: in archaeology and medicine.(FROM THE EDITOR)(El Mirador in Guatemala and cancer treatment)(Editorial)

IT TOOK CHIP BROWN a couple of days to come to grips with El Mirador, the overgrown Maya city in the Guatemalan jungle that dwarfs the better-known Tikal. "Much is still buried," he explains. "You have to stare at the topography awhile before you can quite let go of the idea that the contours and the hills and the little dales are not natural but reflect the buried remnants of a ruined city You just have to overcome this blind spot about how utterly this has all been obliterated." Although El Mirador was discovered some 85 years ago, most of the 15-square-mile site, abandoned nearly 2,000 years ago, has yet to be excavated. "Once you tune into the geography and the topography of the …